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Serial console

The pin headers of the serial console can be reached through the second ventilation below the lower right corner of the sticker on the backside of the device.
Pin 1 is on the right, marked with a white arrow on the PCB, so the pin numbers are counted from right to left. The voltage is 3.3V. Please do *not* connect the VCC pin of the PCB to the VCC pin of you serial interface as this may destroy both of the devices. The pinout is as follows:

For my device, I can only get a connection, if I also connect the VCC pin. May this is a "copy- & paste-error"?

Pin number

4

3

2

1

Function

GND

RX

TX

VCC (3.3V)

Hooking up to the serial with 115200/8N1 enables you to access the brnboot bootloader and save or overwrite the flash contents along with the option to change some settings like MAC address and serial number. You have to enter three spaces immediately after powerup and then enter one exclamation mark (!) to get to the more advanced "Administrator menu".